Composition for the oxidation dyeing of human keratinous fibres

ABSTRACT

The subject of the invention is a composition for the oxidation dyeing of human keratinous fibres and in particular hair comprising, in a cosmetically acceptable medium based on water and at a basic pH, at least one oxidation dye and an alkalinizing agent consisting of sodium metasilicate and aqueous ammonia, and the dyeing method using this composition.

The subject of the invention is a composition for the oxidation dyeingof human keratinous fibres and in particular hair comprising, in acosmetically acceptable medium based on water and at a basic pH, atleast one oxidation dye and an alkalinizing agent consisting of sodiummetasilicate and aqueous ammonia, and the dyeing method using thiscomposition.

It is known to dye human keratinous fibres and in particular hair withdyeing compositions containing oxidation dyes. Oxidation dyes compriseoxidation dye precursors and couplers. Oxidation dye precursors,generally called oxidation bases, are colourless or weakly colouredcompounds which, combined with oxidizing products, can give rise tocoloured and dye compounds by a process of oxidative condensation. Theyare in particular ortho- or para-phenylene diamines ortho- orpara-aminophenols, or heterocyclic bases.

The shades obtained with these oxidation bases may be modified bycombining the said bases with couplers or colour modifiers, the couplersbeing chosen in particular from aromatic meta-diamines,meta-aminophenols, meta-diphenols and certain heterocyclic compounds.

The variety of molecules used in oxidation bases and couplers allows arich palette of colours to be obtained.

The oxidation dyeing method consists in applying to the fibres oxidationbases or a mixture of oxidation bases and couplers with an oxidizingagent, most often hydrogen peroxide, in allowing to act, and then inrinsing the fibres. The application, which is generally carried out at abasic pH, makes it possible to obtain dyeing and simultaneouslylightening of the fibre, which results in practice in the possibility ofobtaining a final coloration which is lighter than the original colour.In addition, the lightening of the fibre has the advantageous effect ofgenerating a uniform colour in the case of grey hair, and in the case ofnaturally pigmented hair, of making the colour stand out, that is to sayof making it more visible.

The lightening of hair is evaluated by the tone height whichcharacterizes the degree or level of lightening. The notion of “tone” isbased on the classification of natural shades, a tone separating eachshade from the one immediately following it or preceding it. Thisdefinition and the classification of natural shades is well known tohair styling professionals and is published in the book “Sciences destraitements capillaires” [Science of hair treatment] by Charles ZVIAK,1988, Ed. Masson, pp. 215 and 278.

The tone heights range from 1 (black) to 10 (light blonde), one unitcorresponding to one tone; the higher the figure, the lighter the shade.

As current lightening oxidation dyeing technology has to make itpossible to obtain a lightening of the fibre of 2 tones to 2 and a halftones, and a covering of hair which is 100% white, it has up until nowinvolved using aqueous ammonia as alkalinizing agent in highconcentrations.

However, as everyone knows, aqueous ammonia has the major disadvantageor releasing a very irritant and unpleasant odour during application ofthe dye. It also sometimes causes, in high concentrations, irritationsof the scalp in the form of pricklings.

Now, after major research studies carried out on the subject, theapplicant has just discovered that it is possible to reduce theirritating odour and the risks of scalp irritation of the said dyeswhile obtaining acceptable lightening levels and intense colorations invaried shades, using, as alkalinizing agent, a mixture of sodiummetasilicate and aqueous ammonia.

This discovery forms the basis of the present invention.

The first subject of the invention is therefore a dyeing composition forthe oxidation dyeing of human keratinous fibres and more particularlyhair, free of oxidizing agent, comprising, in a cosmetically acceptablemedium based on water and at a basic pH, at least one oxidation dye andan alkalinizing agent, characterized in that the alkalinizing agent is acombination of sodium metasilicate and aqueous ammonia.

The expression “dyeing composition” is understood to mean, for thepurposes of the invention, a composition comprising at least oneoxidation dye, which has to be in the presence of an oxidizing agentduring use.

The dyeing composition in accordance with the invention makes itpossible to reduce the amount of aqueous ammonia conventionally usedwhile the dyeing properties are perfectly maintained and makes itpossible to formulate less odorous and less irritating products.

The subject of the invention is also a method for the oxidation dyeingof human keratinous fibres and more particularly hair using the saiddyeing composition. The method consists in mixing, at the time of use, adyeing composition comprising 0.4 to 1.3% by weight of ammonia relativeto the total weight of the dyeing composition, with an oxidizingcomposition comprising hydrogen peroxide or a compound capable ofreleasing hydrogen peroxide in situ, or an oxidoreduction enzyme; theamount of the oxidizing composition being at most 6 times the amount ofthe dyeing composition; the mixture obtained is then applied to thefibres, is allowed to act, after which the fibres are rinsed, optionallywashed with shampoo and rinsed again, and dried.

The invention is also relating to a method for the oxidation dyeing ofhuman keratinous fibres and more particularly hair using the said dyeingcomposition. The method consists in mixing, at the time of use, a dyeingcomposition comprising 1 to 3% by weight of sodium metasilicate,relative to the total weight of the dyeing composition, with anoxidizing composition comprising hydrogen peroxide or a compound capableof releasing hydrogen peroxide in situ, or an oxidoreduction enzyme; theamount of the oxidizing composition being at at least the amount of thedyeing composition; the mixture obtained is then applied to the fibres,is allowed to act, after which the fibres are rinsed, optionally washedwith shampoo and rinsed again, and dried.

Another subject of the invention is a ready-to-use composition for theoxidation dyeing of human keratinous fibres, and more particularly haircomprising the mixture of a dyeing composition described above,comprising 0.4 to 1.3% by weight of ammonia, relative to the totalweight of the dyeing composition, and an oxidizing composition; theamount of the oxidizing composition being at most 6 times the amount ofthe dyeing composition.

Another subject of the invention is a ready-to-use composition for theoxidation dyeing of human keratinous fibres, and more particularly haircomprising the mixture of a dyeing composition described above,comprising 1 to 3% by weight of sodium metasilicate, relative to thetotal weight of the dyeing composition, and an oxidizing composition;the amount of the oxidizing composition being at least the amount of thedyeing composition.

The expression “ready-to-use composition” is understood to mean, for thepurposes of the invention, the composition intended to be applied as itis to keratinous fibres, that is to say that it can be stored as it isbefore use or can result from mixing two compositions immediately beforeuse.

Alkalinizing Agent

The combination according to the invention of sodium metasilicate andaqueous ammonia used as alkalinizing agent should make it possible toadjust the pH of the dyeing composition of the present invention at abasic pH, more particularly at a pH from 7.5 to 13, and preferably from8.5 to 11.5.

According to the present invention, the said combination comprises, asactive substance, more particularly at least 0.1% by weight, preferablyat least 0.5% by weight, and more preferably at least 0.1% by weight ofsodium metasilicate, relative to the total weight of the dyeingcomposition.

Moreover, the amount of sodium metasilicate in the combination isadvantageously of at most 6% by weight, more particularly of at most 5%by weight, and preferably of at most 3% by weight, relative to the totalweight of the dyeing composition.

More particularly, the said combination comprises, as active substance,from 0.1 to 6% by weight approximately of sodium metasilicate,preferably from 0.5 to 5%, and more particularly from 1 to 3% relativeto the total weight of the dyeing composition.

According to the present invention, the said combination comprises, asactive substance, more particularly at least 0.1% by weight, preferablyat least 0.4% by weight, and more preferably at least 0.6% by weight ofammonia, relative to the total weight of the dyeing composition.

Moreover, the amount of ammonia in the combination is more especially ofat most 1.6% by weight, preferably of at most 1.3% by weight, morepreferably of at most 1.2% by weight, and more particularly of at most1% by weight, relative to the total weight of the dyeing composition.

More particularly, the combination comprises from 0.1 to 1.6% by weightapproximately of ammonia, preferably from 0.4 to 1.3% by weight, moreparticularly from 0.4 to 1.2% by weight, and more preferably from 0.6 to1% by weight, relative to the total weight of the dyeing composition.

It has to be mentioned that according to one advantageous embodiment ofthe invention, the weight ratio of ammonia to sodium metasilicate iscomprised between 0.02 and 15, more particularly between 0.1 and 5,preferably between 0.3 and 2, and more preferably between 0.4 and 1.

According to the present invention, sodium metasilicate [Na₂SiO₃] is ananhydrous compound, but it can also exist in its hydrated forms with 5or 9 molecules of water. Ammonia is introduced into the formulae in theform of aqueous ammonia, which is an aqueous solution of ammonia. Theaqueous ammonia generally used has a titre of 20 to 25% by weight ofammonia.

The present invention makes it possible to reduce the amount of aqueousammonia on the basis of an aqueous solution having a titre of 20.5%ammonia, from 20 to 80% and more particularly from 30 to 60%.

Medium

The cosmetically acceptable medium for dyeing in accordance with theinvention consists of water or of a mixture of water and at least oneorganic solvent for solubilizing the compounds which might not besufficiently soluble in water. As organic solvent, there may bementioned, for example, C₁-C₄ alkanols, such as ethanol and isopropanol;glycerol; glycols and glycol ethers such as 2-butoxyethanol, propyleneglycol, monomethyl ether of propylene glycol, monoethyl ether andmonomethyl ether of diethylene glycol, and aromatic alcohols such asbenzyl alcohol or phenoxyethanol, analogous products and mixturesthereof.

The solvents may be present in proportions preferably ranging from 1 to40% by weight approximately relative to the total weight of the dyeingcomposition, and still more preferably from 5 to 30% by weightapproximately.

Oxidation Dyes

The oxidation dyes which can be used according to the invention arechosen from oxidation bases and/or couplers.

Preferably, the compositions according to the invention contain at leastone oxidation base.

The oxidation bases are chosen from those conventionally known inoxidation dyeing, and among which there may be mentioned in particularortho- and para-phenylenediamines, double bases, ortho- andpara-aminophenols, the following heterocyclic bases and their additionsalts with an acid.

There may be mentioned in particular:

-   -   (I) the para-phenylenediamines of the following formula (I) and        their addition salts with an acid:        in which:

-   R₁ represents a hydrogen atom, a C₁-C₄ alkyl radical, a    monohydroxy(C₁-C₄ alkyl) radical, a polyhydroxy-(C₂-C₄ alkyl)    radical, a (C₁-C₄)alkoxy(C₁-C₄)alkyl radical, a C₁-C₄ alkyl radical    substituted with a nitrogen-containing group, a phenyl radical or a    4′-aminophenyl radical;

-   R₂ represents a hydrogen atom, a C₁-C₄ alkyl radical, a    monohydroxy(C₁-C₄ alkyl) radical, a polyhydroxy(C₂-C₄ alkyl) radical    a with radical or a C₁-C₄ alkyl radical substituted with a    nitrogen-containing group;

-   R₁ and R₂ may also form with the nitrogen atom carrying them a 5- or    6-membered nitrogen-containing heterocycle optionally substituted    with one or more alkyl, hydroxyl or ureido groups;

-   R₃ represents a hydrogen atom, a halogen atom such as a chlorine    atom, a C₁-C₄ alkyl radical, a sulpho radical, a carboxyl radical, a    monohydroxy(C₁-C₄ alkyl) radical, a hydroxy(C₁-C₄ alkoxy) radical,    an acetylamino(C₁-C₄ alkoxy) radical, a mesylamino(C₁-C₄ alkoxy)    radical or a carbamoylamino(C₁-C₄ alkoxy) radical,

-   R₄ represents a hydrogen or halogen atom or a C₁-C₄ alkyl radical.

Among the nitrogen-containing groups of formula (I) above, there may bementioned in particular the amino, mono(C₁-C₄)alkylamino,(C₁-C₄)dialkylamino, (C₁-C₄)trialkylamino, monohydroxy(C₁-C₄)alkylamino,imidazolinium and ammonium radicals.

Among the para-phenylenediamines of formula (I) above, there may bementioned more particularly para-phenylenediamine, para-tolylenediamine,2-chloro-paraphenylenediamine, 2,3-dimethyl-para-phenylenediamine,2,6-dimethyl-para-phenylenediamine, 2,6-diethyl-para-phenylenediamine,2,5-dimethyl-para-phenylenediamine, N,N-dimethyl-para-phenylenediamine,N,N-diethyl-para-phenylenediamine, N,N-dipropyl-para-phenylenediamine,4-amino-N,N-diethyl-3-methylaniline,N,N-bis(β-hydroxyethyl)-para-phenylenediamine,4-N,N-bis(5-hydroxyethyl)amino-2-methylaniline,4-N,N-bis(5-hydroxy-ethyl)amino-2-chloroaniline,2-β-hydroxyethyl-para-phenylenediamine, 2-fluoro-para-phenylenediamine,2-isopropyl-para-phenylenediamine,N—(O-hydroxypropyl)-para-phenylenediamine,2-hydroxymethyl-para-phenylenediamine,N,N-dimethyl-3-methyl-para-phenylenediamine,N,N-(ethyl-β-hydroxyethyl)-para-phenylenediamine,N—(β,γ-dihydroxypropyl)-para-phenylenediamine,N-(4′-aminophenyl)-para-phenylenediamine,N-phenyl-para-phenylenediamine,2-O-hydroxyethyloxy-para-phenylenediamine,2-A-acetylamino-ethyloxy-para-phenylenediamine,N-(β-methoxyethyl)-para-phenylene-diamine,2-methyl-1-N-5-hydroxyethyl-para-phenylenediamine,N-(4-aminophenyl)-3-hydroxy-pyrrolidine, and their addition salts withan acid.

Among the para-phenylenediamines of formula (I) above, there are mostparticularly preferred para-phenylenediamine, para-tolylenediamine,2-isopropyl-paraphenylene-diamine,2-β-hydroxyethyl-para-phenylenediamine,2-O-hydroxyethyloxy-para-phenylene-diamine,2,6-dimethyl-para-phenylenediamine, 2,6-diethyl-para-phenylenediamine,2,3-dimethyl-para-phenylenediamine,N,N-bis(β-hydroxyethyl)-para-phenylenediamine,2-chloro-para-phenylenediamine, and their addition salts with an acid.

-   -   (II) According to the invention, “double bases” is understood to        mean the compounds containing at least two aromatic rings on        which amino and/or hydroxyl groups are carried.

Among the double bases which can be used as oxidation bases in thedyeing compositions in accordance with the invention, there may bementioned in particular the compounds corresponding to the followingformula (II), and their addition salts with an acid:

in which:

-   -   Z₁ and Z₂, which are identical or different, represent a        hydroxyl or —NH₂ radical which may be substituted with a C₀-C₄        alkyl radical or with a linking arm Y;    -   the linking arm Y represents a linear or branched alkylene chain        comprising from 1 to 14 carbon atoms, which may be interrupted        by or which may end with one or more nitrogen-containing groups        and/or one or more heteroatoms such as oxygen, sulphur or        nitrogen atoms, and optionally substituted with one or more        hydroxyl or C₁-C₆ alkoxy radicals;    -   R₅ and R₆ represent a hydrogen or halogen atom, a C₁-C₄ alkyl        radical, a monohydroxy(C₁-C₄ alkyl) radical, a polyhydroxy(C₂-C₄        alkyl) radical, an amino(C₁-C₄ alkyl) radical or a linking arm        Y;    -   R₇, R₈, R₉, R₁₀, R₁₁ and R₁₂, which are identical or different,        represent a hydrogen atom, a linking arm Y or a C₁-C₄ alkyl        radical;    -   it being understood that the compounds of formula (II) contain        only one linking arm Y per molecule.

Among the nitrogen-containing groups of formula (II) above, there may bementioned in particular the amino, mono(C₁-C₄)alkylamino,(C₁-C₄)dialkylamino, (C₁-C₄)trialkylamino, monohydroxy(C₁-C₄)alkylamino,imidazolinium and ammonium radicals.

Among the double bases of formulae (II) above, there may be mentionedmore particularlyN,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-aminophenyl)-1,3-diaminopropanol,N,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-aminophenyl)ethylenediamine,N,N′-bis(4-aminophenyl)-tetramethylenediamine,N,N′-bis(β-hydroxyethyl)-N,N′-bis(4-aminophenyl)tetramethylene-diamine,N,N′-bis(4-methylaminophenyl)tetramethylenediamine,N,N′-bis(ethyl)-N,N′-bis(4′-amino-3′-methylphenyl)ethylene-diamine,1,8-bis(2,5-diaminophenoxy)-3,5-dioxaoctane, and their addition saltswith an acid.

Among these double bases of formula (II),N,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-10aminophenyl)-1,3-diaminopropanol,1,8-bis(2,5-diaminophenoxy)-3,5-dioxaoctane or one of their additionsalts with an acid are particularly preferred.

-   -   (III) The para-aminophenols corresponding to the following        formula (III), and their addition salts with an acid:        in which:    -   R₁₃ represents a hydrogen atom, or a halogen atom such as        fluorine, a C₁-C₄ alkyl, monohydroxy(C₁-C₄ alkyl),        (C₁-C₄)alkoxy(C₁-C₄)-alkyl, amino(C₁-C₄ alkyl) or        hydroxy(C₁-C₄)alkylamino-(C₁-C₄ alkyl) radical,    -   R₁₄ represents a hydrogen atom, or a halogen atom such as        fluorine, a C₁-C₄ alkyl, monohydroxy(C₁-C₄ alkyl),        polyhydroxy(C₂-C₄ alkyl), amino(C₁-C₄ alkyl), cyano(C₁-C₄ alkyl)        or (C₁-C₄)alkoxy(C₁-C₄)alkyl radical.

Among the para-aminophenols of formula (III) above, there may bementioned more particularly para-aminophenol, 4-amino-3-methylphenol,4-amino-3-fluorophenol, 4 amino-3-hydroxymethylphenol,4-amino-2-methylphenol, 4-amino-2-hydroxymethyl-phenol,4-amino-2-methoxymethylphenol, 4-amino-2-aminomethylphenol,4-amino-2-(β-hydroxyethylaminomethyl)phenol, and their addition saltswith an acid.

-   -   (IV) The ortho-aminophenols which can be used as oxidation bases        in the context of the present invention are chosen in particular        from 2-aminophenol, 2-amino-1-hydroxy-5-methylbenzene,        2-amino-1-hydroxy-6-methylbenzene, 5-acetamido-2-aminophenol,        and their addition salts with acid.    -   (V) Among the heterocyclic bases which can be used as oxidation        bases in the dyeing compositions in accordance with the        invention, there may be mentioned more particularly pyridine        derivatives, pyrimidine derivatives, pyrazole derivatives, and        their addition salts with an acid.

Among the pyridine derivatives, there may be mentioned more particularlythe compounds described for example in Patents GB 1,026,978 and GB1,153,196, such as 2,5-diaminopyridine,2-(4-methoxyphenyl)amino-3-aminopyridine, 2,3-diamino-6-methoxypyridine,2-(β-methoxyethyl)amino-3-amino-6-methoxypyridine, 3,4-diamino-pyridine,and their addition salts with an acid.

Among the pyrimidine derivatives, there may be mentioned moreparticularly the compounds described, for example, in Pat. DE 2,359,399;JP 88-169 571; JP 91-10659 or Patent Application WO 96/15765, such as2,4,5,6-tetraminopyrimidine, 4-hydroxy-2,5,6-triaminopyrimidine,2-hydroxy-4,5,6-triaminopyrimidine, 2,4-dihydroxy-5,6-diaminopyrimidine,2,5,6-triamino-pyrimidine, and the pyrazolopyrimidine derivatives suchas those mentioned in Patent Application FR-A-2 750 048 and among whichthere may be mentioned pyrazolo[1,5-a]-pyrimidine-3,7-diamine;2,5-dimethyl-pyrazolo[1,5-a]-pyrimidine-3,7-diamine;pyrazolo[1,5-a]pyrimidine-3,5-diamine;2,7-dimethylpyrazolo[1,5-a]pyrimidine-3,5-diamine;3-aminopyrazolo[1,5-a]pyrimidin-7-ol;3-amino-pyrazolo[1,5-a]pyrimidin-5-ol;2-(3-amino-pyrazolo-[1,5-a]pyrimidin-7-ylamino)ethanol,2-(7-amino-pyrazolo[1,5-a]pyrimidin-3-ylamino)ethanol,2-[(3-amino-pyrazolo[1,5-a]pyrimidin-7-yl)-(2-hydroxy-ethyl)amino]-ethanol,2-[(7-aminopyrazolo[1,5-a]-pyrimidin-3-yl)-(2-hydroxyethyl)amino]ethanol, 5,6-dimethylpyrazolo-[1,5-a]pyrimidine-3,7-diamine,2,6-dimethyl-pyrazolo-[1,5-a]pyrimidine-3,7-diamine,2,5,N7,N7-tetramethyl-pyrazolo[1,5-a]pyrimidine-3,7-diamine,3-amino-5-methyl-7-imidazolylpropyl-aminopyrazolo[1,5-a]-pyrimidine,their addition salts and their tautomeric forms, when a tautomericequilibrium exists and their addition salts with an acid.

Among the pyrazole derivatives, there may be mentioned more particularlythe compounds described in Pat. DE 3,843,892, DE 4 133 957 and PatentApplications WO 94/08969, WO 94/08970, FR-A-2 733 749 and DE 195 43 988such as 4,5-diamino-1-methylpyrazole, 3,4-diaminopyrazole,4,5-diamino-1-(4′-chlorobenzyl)-pyrazole,4,5-diamino-1,3-dimethylpyrazole, 4,5-diamino-3-methyl-1-phenylpyrazole,4,5-diamino-1-methyl-3-phenylpyrazole,4-amino-1,3-dimethyl-5-hydrazino-pyrazole,1-benzyl-4,5-diamino-3-methyl-pyrazole,4,5-diamino-3-tert-butyl-1-methylpyrazole,4,5-diamino-1-tert-butyl-3-methylpyrazole,4,5-diamino-1-(β-hydroxyethyl)-3-methylpyrazole,4,5-diamino-1-(β-hydroxyethyl)pyrazole,4,5-diamino-1-ethyl-3-methylpyrazole,4,5-diamino-1-ethyl-3-(4′-methoxyphenyl)pyrazole,4,5-diamino-1-ethyl-3-hydroxy-methylpyrazole,4,5-diamino-3-hydroxymethyl-1-methylpyrazole,4,5-diamino-3-hydroxymethyl-1-isopropyl-pyrazole,4,5-diamino-3-methyl-1-isopropyl-pyrazole,4-amino-5-(2′-aminoethyl)amino-1,3-dimethyl-pyrazole,3,4,5-triaminopyrazole, 1-methyl-3,4,5-triamino-pyrazole,3,5-diamino-1-methyl-4-methylaminopyrazole,3,5-diamino-4-(O-hydroxy-ethyl)amino-1-methylpyrazole, and theiraddition salts with an acid.

According to the present invention, the oxidation bases preferablyrepresent from 0.0005 to 12% by weight approximately of the total weightof the composition, and still more preferably from 0.005 to 8% by weightapproximately of this weight.

The couplers which can be used in the dyeing composition according tothe invention are those conventionally used in oxidation dyeingcompositions, that is to say meta-aminophenols, meta-phenylenediamines,meta-diphenols, naphthols and heterocyclic couplers such as, forexample, indole derivatives, indoline derivatives, sesamol and itsderivatives, pyridine derivatives, pyrazolotriazole derivatives,pyrazolones, indazoles, benzimidazoles, benzothiazoles, benzoxazoles,1,3-benzodioxoles, quinolines and their addition salts with an acid.

These couplers are more particularly chosen from2,4-diamino-1-(O-hydroxyethyloxy)benzene, 2-methyl-5-aminophenol,5-N—(β-hydroxyethyl)amino-2—methylphenol, 3-aminophenol,2-chloro-3-amino-6-methylphenol, 1,3-dihydroxybenzene,1,3-dihydroxy-2-methylbenzene, 4-chloro-1,3-dihydroxybenzene,2-amino-4-(β-hydroxy ethylamino)-1-methoxybenzene, 1,3-diaminobenzene,1,3-bis(2,4-diaminophenoxy)-propane, sesamol,1-amino-2-methoxy-4,5-methylene-dioxybenzene, α-naphthol,6-hydroxyindole, 4-hydroxyindole, 4-hydroxy-N-methylindole,6-hydroxy-indoline, 2,6-dihydroxy-4-methylpyridine,1-H-3-methylpyrazol-5-one, 1-phenyl-3-methylpyrazol-5-one,2-amino-3-hydroxypyridine, 3,6-dimethyl-pyrazolo[3,2-c]-1,2,4-triazole,2,6-dimethyl-pyrazolo[1,5-b]-1,2,4-triazole and their addition saltswith an acid.

When they are present, these couplers preferably represent from 0.0001to 10% by weight approximately of the total weight of the composition,and still more preferably from 0.005 to 5% by weight approximately.

In general, the addition salts with an acid of the oxidation bases andcouplers are chosen in particular from the hydrochlorides,hydrobromides, sulphates, tartrates, lactates and acetates.

The composition according to the invention may also contain, in additionto the oxidation dyes defined above, direct dyes for enriching theshades with glints. These direct dyes may then be chosen in particularfrom neutral, cationic or anionic nitro, azo or anthraquinone dyes inthe proportion by weight of about 0.001 to 20%, and preferably 0.01 to10% of the total weight of the composition.

Adjuvants

The dyeing composition in accordance with the invention may also containvarious adjuvants which are conventionally used in hair dyeingcompositions, such as anionic, cationic, nonionic, amphoteric orzwitterionic surfactants or mixtures thereof, fatty alcohols, fattyacids, anionic, cationic, nonionic, amphoteric or zwitterionic polymersor mixtures thereof, inorganic or organic thickening agents orthickening polymers such as, for example, nonionic guar gums,associative polymers containing at least one hydrophilic unit and atleast one fatty chain and of a nonionic, anionic, cationic or amphotericnature, antioxidants or reducing agents, penetrating agents,sequestering agents such as EDTA and etidronic acid, UV-screeningagents, waxes, perfumes, buffers, dispersing agents, conditioning agentssuch as, for example, modified or unmodified, volatile or nonvolatilesilicones, film-forming agents, pearlescent agents, preservatives,ceramides, pseudoceramides, vegetable, mineral or synthetic oils,vitamins or provitamins such as panthenol, opacifiers, and the like.

Preferably, the dyeing composition of the invention contains at leastone cationic polymer in the proportion of about 0.05 to 10% by weight,and at least one surfactant, which is preferably nonionic, in theproportion of 0.1 to 20% by weight.

Preferably, it also contains at least one thickening polymer preferablychosen from associative polymers in the proportion of about 0.05 to 10%by weight.

The reducing agents or antioxidants may be chosen in particular fromsodium sulphite, thioglycolic acid and thiolactic acid and their saltsof ammonium, sodium bisulphite, dehydroascorbic acid, hydroquinone,2-methylhydroquinone, tert-butylhydroquinone, homogentisic acid, andthey are then generally present in quantities ranging from about 0.05 to3% by weight relative to the total weight of the composition.

Of course, persons skilled in the art will be careful to choose this orthese possible additional compounds such that the advantageousproperties intrinsically attached to the dyeing composition inaccordance with the invention are not, or not substantially, impaired bythe addition(s) envisaged.

According to a first embodiment, the dyeing method according to theinvention comprises the following steps: there are mixed, at the time ofuse, a dyeing composition as described above and in particularcomprising, in a cosmetically acceptable medium based on water and at abasic pH, at least one oxidation dye and a combination of sodiummetasilicate and aqueous ammonia, the amount of ammonia being from 0.4to 1.3% by weight relative to the total weight of the dyeingcomposition, with an oxidizing composition; the amount of the oxidizingcomposition being at most 6 times the weight of the dyeing composition,the mixture obtained is then applied to the keratinous fibres, it isallowed to act, after which the keratinous fibres are rinsed, optionallywashed with shampoo and rinsed again, then dried.

According to a particular embodiment of the invention, the weight ratiodyeing composition/oxidizing composition is comprised between 2/1 and1/6, and preferably between 1/1 and 1/3.

According to a second embodiment, the dyeing method according to theinvention comprises the following steps: there are mixed, at the time ofuse, a dyeing composition as described above and in particularcomprising, in a cosmetically acceptable medium based on water and at abasic pH, at least one oxidation dye and a combination of sodiummetasilicate and aqueous ammonia, the amount of sodium metasilicatebeing from 1 to 3% by weight relative to the total weight of the dyeingcomposition, with an oxidizing composition; the amount of the oxidizingcomposition being at least the weight of the dyeing composition, themixture obtained is then applied to the keratinous fibres, it is allowedto act, after which the keratinous fibres are rinsed, optionally washedwith shampoo and rinsed again, then dried.

According to a particular embodiment of the invention, the weight ratiodyeing composition/oxidizing composition is comprised between 1/1 and1/6, and preferably between 1/1 and 1/3.

The pH of the composition is ranging more particularly from 7.5 to 13.

Moreover, the said mixture is advantageously allowed to act for 3 to 50minutes approximately, preferably 5 to 30 minutes approximately.

The dyeing composition, before mixing with the oxidant, may be invarious forms, such as a liquid, cream or gel form, optionallypressurized or in any other form appropriate for carrying out, aftermixing, a dyeing of human keratinous fibres and in particular hair.

Oxidant

In the oxidizing composition, the oxidizing agent is chosen fromhydrogen peroxide and compounds capable of releasing hydrogen peroxidein situ, oxidoreduction enzymes such as laccases, peroxidases andoxidoreductases containing 2 electrons (such as uricase), whereappropriate in the presence of their respective donor or cofactor.

The use of hydrogen peroxide is particularly preferred. This oxidizingagent advantageously consists of a solution of hydrogen peroxide whosetitre may vary, more particularly, from about 1 to 40 volumes, and stillmore preferably from about 5 to 40.

According to a first embodiment of the invention, the ready-to-usecomposition for the oxidation dyeing of human keratinous fibres, andmore particularly hair comprising the mixture of a dyeing compositiondescribed above, comprising 0.4 to 1.3% by weight of ammonia, relativeto the total weight of the dyeing composition, with an oxidizingcomposition; the amount of the oxidizing composition being at most 6times the amount of the dyeing composition.

More especially, the weight ratio dyeing composition/oxidizingcomposition is comprised between 2/1 and 1/6, and preferably between 1/1and 1/3.

A second embodiment consists in a ready-to-use composition for theoxidation dyeing of human keratinous fibres, and more particularly haircomprising the mixture of a dyeing composition described above,comprising 1 to 3% by weight of sodium metasilicate, relative to thetotal weight of the dyeing composition, with an oxidizing composition;the amount of the oxidizing composition being at least the amount of thedyeing composition.

More especially, the weight ratio dyeing composition/oxidizingcomposition is comprised between 1/1 and 1/6, and preferably between 1/1and 1/3.

The examples which follow are intended to illustrate the inventionwithout, however, exhibiting a limiting character.

EXAMPLES 1-3

The following dyeing compositions were prepared:

(amounts expressed in grams of active substance) Example 1 Example 2Example 3 Para-phenylenediamine . . . 0.24 0.24 0.24 Para-aminophenol .. . 0.44 0.44 0.44 2-aminophenol . . . 0.028 0.028 0.0281,3-dihydroxybenzene . . . 0.192 0.192 0.192 3-aminophenol . . . 0.0190.019 0.019 5-N-(β-hydroxyethyl)amino-2-methylphenol . . . 0.021 0.0210.021 1,3-dihydroxy-2-methylbenzene . . . 0.055 0.055 0.055 Anhydroussodium metasilicate . . . 2 2 2 Ammonia (Aqueous ammonia containing 1.231.23 1.23 20.5% Wt of NH₃) . . . Reducing agent, antioxidant,sequestrant, q.s. q.s. q.s. perfume . . . Propylene glycol . . . 10 1010 Anionic polymer: crosslinked polyacrylic acid. 0.4 0.4 0.4 Amphotericpolymer: polyquaternium 22 1.5 1.5 (C.T.F.A. name) Merquat 280 sold bythe company CALGON . . . Cationic polymer: polyquaternium 6 (C.T.F.A 2.8name) Merquat 100 sold by the company MERCK . . . Cationic polymer:Hexadimethrine Chloride 3 3 (C.T.F.A. name) Mexomer PO sold by thecompany CHIMEX . . . Anionic surfactant: powdered sodium lauryl 3sulphate . . . Nonionic surfactant: oxyethylenated lauryl 7.5 7.5alcohol containing 12 mol of ethylene oxide . . . Nonionic surfactant:oxyethylenated oleocetyl 4 4 alcohol containing 30 mol of ethylene oxide. . . Nonionic surfactant: oxyethylenated decyl 10 10 10 alcoholcontaining 3 mol of ethylene oxide . . . Nonionic surfactant:oxyethylenated decyl 8 alcohol containing 5 mol of ethylene oxide . . .Lauric acid . . . 2.5 2.5 Cetylstearyl alcohol 50/50 . . . 11.5 11.5Pearlescent agent: hydrophobic pyrogenic 1.2 1.2 silica . . .Pearlescent agent: glyceryl monostearate . . . 2 2 Demineralized water .. . qs . . . 100 100

At the time of use, each dyeing composition described above is mixedweight for weight with a solution of hydrogen peroxide at 20 volumes (6%by weight).

The mixtures thus prepared were applied for 30 minutes to locks ofnatural or permanently waved grey hair which is 90% white. The lockswere then rinsed, washed with a standard shampoo, rinsed again and thendried.

It was observed that these mixtures were a lot less odorous than thoseof the prior art with satisfactory application qualities.

The hair was dyed in a strong shade of golden blonde colour for each ofExamples 1 to 3.

Compared with prior art compositions which are identical except thatthey do not contain sodium metasilicate and have a much higher contentof ammonia of about 2% as active substance, the dyeing performances ofcompositions 1 to 3 were preserved.

1. Dyeing composition for the oxidation dyeing of human keratinousfibres and more particularly hair, free of oxidizing agent, comprising,in a cosmetically acceptable medium based on water and at a basic pH, atleast one oxidation dye and an alkalinizing agent, characterized in thatthe alkalinizing agent is a combination of sodium metasilicate andaqueous ammonia.
 2. Dyeing Composition according to claim 1,characterized in that the alkalinizing agent comprises, as activesubstance, at least 0.1% by weight, preferably at least 0.5% by weight,and more preferably at least 1% by weight of sodium metasilicaterelative to the total weight of the dyeing composition.
 3. DyeingComposition according to claims 1 or 2, characterized in that thealkalinizing agent comprises, as active substance, at most 6% by weight,preferably at most 5% by weight, and more preferably at most 3% byweight of sodium metasilicate relative to the total weight of the dyeingcomposition.
 4. Dyeing Composition according to anyone of the precedingclaims, characterized in that the alkalinizing agent comprises, asactive substance, from 0.1 to 6% by weight of sodium metasilicaterelative to the total weight of the dyeing composition.
 5. DyeingComposition according to anyone of the preceding claims, characterizedin that the alkalinizing agent comprises, as active substance, from 0.5to 5% by weight of sodium metasilicate relative to the total weight ofthe dyeing composition.
 6. Dyeing Composition according to anyone of thepreceding claims, characterized in that the alkalinizing agentcomprises, as active substance, from 1 to 3% by weight of sodiummetasilicate relative to the total weight of the dyeing composition. 7.Dyeing Composition according to any one of the preceding claims,characterized in that the alkalinizing agent comprises, as activesubstance, at least 0.1% by weight, more particularly at least 0.4% byweight, and preferably at least 0.6% by weight of ammonia relative tothe total weight of the dyeing composition.
 8. Dyeing Compositionaccording to any one of the preceding claims, characterized in that thealkalinizing agent comprises, as active substance, at most 1.6% byweight, more particularly at least 1.3% by weight, preferably at least1.2% by weight, and more preferably at least 1% by weight of ammoniarelative to the total weight of the dyeing composition.
 9. DyeingComposition according to any one of the preceding claims, characterizedin that the alkalinizing agent comprises, as active substance, from 0.1to 1.6% by weight of ammonia relative to the total weight of the dyeingcomposition.
 10. Dyeing Composition according to claim 5, characterizedin that the alkalinizing agent comprises, as active substance, from 0.4to 1.3% by weight, preferably of from 0.4 to 1.2% by weight of ammoniarelative to the total weight of the dyeing composition.
 11. DyeingComposition according to claim 6, characterized in that the alkalinizingagent comprises, as active substance, from 0.6 to 1% by weight ofammonia relative to the total weight of the dyeing composition. 12.Dyeing Composition according to any one of the preceding claims,characterized in that its pH is from 7.5 to 13, preferably from 8.5 to11.5.
 13. Dyeing Composition according to any one of the precedingclaims, characterized in that the oxidation dye or dyes are chosen fromoxidation bases and couplers.
 14. Dyeing Composition according to claim13, characterized in that it comprises at least one oxidation base. 15.Dyeing Composition according to claim 14, characterized in that theoxidation bases are chosen from the group consisting of ortho- andpara-phenylenediamines, double bases, ortho- and para-aminophenols,heterocyclic bases and their addition salts with an acid.
 16. DyeingComposition according to claim 15, characterized in that the couplersare chosen from the group consisting of meta-aminophenols,meta-phenylene-diamines, meta-diphenols, naphthols, indole derivatives,indoline derivatives, sesamol and its derivatives, pyridine derivatives,pyrazolotriazole derivatives, pyrazolones, indazoles, benzimidazoles,benzothiazoles, benzoxazoles, 1,3-benzodioxoles, quinolines and theiraddition salts with an acid.
 17. Dyeing Composition according to any oneof claims 13 to 15, characterized in that the addition salts with anacid of the oxidation bases and couplers are chosen from thehydrochlorides, hydrobromides, sulphates, tartrates, lactates andacetates.
 18. Dyeing Composition according to any one of the precedingclaims, characterized in that the oxidation base or bases are present ata concentration ranging from 0.0005 to 12% by weight relative to thetotal weight of the dyeing composition.
 19. Dyeing Composition accordingto any one of the preceding claims, characterized in that the coupler orcouplers are present at a concentration between 0.0001 and 10% by weightrelative to the total weight of the dyeing composition.
 20. DyeingComposition according to any one of the preceding claims, characterizedin that the cosmetically acceptable medium based on water comprises atleast one organic solvent.
 21. Dyeing Composition according to claim 20,characterized in that the organic solvent or solvents are present inproportions ranging from 1 to 40% by weight relative to the total weightof the dyeing composition.
 22. Dyeing Composition according to any oneof the preceding claims, characterized in that it contains at least onecationic polymer in the proportion from 0.05 to 10% by weight and atleast one nonionic surfactant in the proportion from 0.1 to 20% byweight relative to the total weight of the dyeing composition. 23.Method for dyeing human keratinous fibres and in particular hair,characterized in that there are mixed, at the time of use, a dyeingcomposition as described in any one of claims 2 to 6 and 10 to 22, withan oxidizing composition comprising hydrogen peroxide or a compoundcapable of releasing hydrogen peroxide in situ, or an oxidoreductionenzyme; the amount of the oxidizing composition being of at most 6 timesthe amount of the dyeing composition, in that the mixture obtained isapplied to the fibres, is allowed to act, after which the fibres arerinsed, optionally washed with shampoo and rinsed again, then dried. 24.Method according to the preceding claim, characterized in that theweight ratio dyeing composition/oxidizing composition is comprisedbetween 2/1 and 1/6, preferably between 1/1 and 1/3.
 25. Method fordyeing human keratinous fibres and in particular hair, characterized inthat there are mixed, at the time of use, a dyeing composition asdescribed in any one of claims 6 to 22, with an oxidizing compositioncomprising hydrogen peroxide or a compound capable of releasing hydrogenperoxide in situ, or an oxidoreduction enzyme; the amount of theoxidizing composition being of at least the amount of the dyeingcomposition, in that the mixture obtained is applied to, the fibres, isallowed to act, after which the fibres are rinsed, optionally washedwith shampoo and rinsed again, then dried.
 26. Method according to thepreceding claim, characterized in that the weight ratio dyeingcomposition/oxidizing composition is comprised between 1/1 and 1/6,preferably between 1/1 and 1/3.
 27. Ready-to-use composition for theoxidation dyeing of human keratinous fibres and in particular hair,characterized in that it comprises the mixture of a dyeing compositiondefined in any one of claims 2 to 6 and 10 to 22, with an oxidizingcomposition; the amount of the oxidizing composition being of at most 6times the amount of the dyeing composition.
 28. Ready-to-use compositionaccording to claims 26 or 27, characterized in that the weight ratiodyeing composition/oxidizing composition is comprised between 2/1 and1/6, preferably between 1/1 and 1/3.
 29. Ready-to-use composition forthe oxidation dyeing of human keratinous fibres and in particular hair,characterized in that it comprises the mixture of a dyeing compositiondefined in any one of claims 6 to 22, with an oxidizing composition; theamount of the oxidizing composition being of at least the amount of thedyeing composition.
 30. Ready-to-use composition according to claims 28or 29, characterized in that the weight ratio dyeingcomposition/oxidizing composition is comprised between 1/1 and 1/6,preferably between 1/1 and 1/3.
 31. Ready-to-use composition accordingto anyone of claims 27 to 30, characterized in that the oxidizingcomposition comprises hydrogen peroxide.